On Monday, 23 October 2017 at 11:02:41 UTC, Martin Nowak wrote:
On Monday, 23 October 2017 at 06:05:50 UTC, drug wrote:
20.10.2017 17:46, Martin Nowak пишет:
My 2 cent:
1. dub needs ability to work with other repository than
standard ones.
You mount or clone whatever you want and use `dub add-local`.
2. multicore building - entire project in D builds faster than
C++ one (I have two implementation of the same), but in case
of incremental building C++ faster.
I always assumed this to be the main point why people are
asking for a better build tool, but it's not sth. dub can do
atm. It's a limitation of the compiler that requires various
changes and a slight redesign of our build model.
Does it? Reggae can do parallel per-package builds (in fact, the
default) right now.
In C++ incremental rebuilds are simple as you compile each file
individually anyhow, but that's the crux for why C++
compilations are so slow in the first place.
Not really. C++ is slow to compile anyway because parsing it is
slow. C has the same compilation model and is much much faster to
compile than C++. There's also the fact that the same headers are
parsed over and over again. `#include <iostream>` requires
parsing thousands of lines of code from dozens of files.
However, if all you touched was a C++ implementation file, then
incremental builds are faster than D. Really.
Compiling multiple modules at once provides lots of speedups as
you do not have to reparse and analyze common/mutual imports,
but on the downside it cannot be parallelized that well.
I measured, and indeed compiling per package is faster than
compiling all of the modules that have to be recompiled
individually, even if done in parallel. Weirdly enough this is a
disadvantage (time-wise) of having implementation and
declarations in the same file.
Dub could parallelize building individual packages/sub-packages
(target + dependencies) right now though.
reggae already does, just point it at a dub package directory. By
default it'll even build the default target and a unittest one in
parallel.
3. dub single build mode does not caches builds so it builds
entire project every time.
Could you please file an issue with a test case for that.
Why do you use single build mode in the first place?
I'd assume it'd be to only rebuild the necessary files C++-style.
However, and as stated by you above, that's usually slower anyway.
Atila
